For example, graphic equalizers are recognized as representatives of sound effect adjustment with respect to sound signals (for example, refer to PTL 1).
In graphic equalizers, for example, by raising or lowering knobs of a slide bar which correspond to each frequency component of the sound signal as shown in FIG. 1, gain (equalizer) adjustment of these frequency components is performed.
That is, in the graphic equalizer shown in FIG. 1, a knob PH 11 which corresponds to 100 Hz, a knob PH 12 which corresponds to 500 Hz, and a knob PH 13 which corresponds to 10 kHz are provided. Here, in the example of FIG. 1, the adjustable frequencies are 100 Hz, and 500 Hz, thereafter skipping to 10 kHz; however, although between 500 Hz and 10 kHz is omitted in order to simplify the description, this does not mean there is nothing there in practice.
The knob PH 11 to the knob PH 13 are arranged on scales where each numeric value is recorded from “+3” to “−3” and the user adjusts the gain of each frequency component corresponding to each knob by operating these knobs so as to move on the predetermined scale. In this example, the knob PH 11 is positioned on a scale where “+1” is recorded, the knob PH 12 is positioned on a scale where “−1” is recorded, and the knob PH 13 is positioned on a scale where “+2” is recorded.
Due to this, in the figure, it is possible to obtain the characteristics shown on the right side. In other words, the gain of each frequency of the sound signals is amplified or attenuated by an amount according to the positions of the knobs. Here, in the figure, the horizontal axis and the vertical axis on the right side show the respective frequencies and the gains of each frequency. In this example, the gain of the 100 Hz and 10 kHz are amplified by an amount which corresponds to the positions of the knob PH 11 and the knob PH 13 and the gain of the 500 Hz is attenuated by an amount which corresponds to the position of the knob PH 12.
In this manner, the adjustment of the sound effects of the graphic equalizer or the like is widely and generally performed.